DE3032844A1 - HEATING OR HEAT TREATMENT PLANT - Google Patents

Description

29 Aug 1980

DipUng.W.DaMU

DipL-lng. H.-J. Upper *

Patent attorneys Frankenforster Straßa 137 5060 Bergisch Gladbach 3

Iiuossavaara-Kiirunavaara Aktiebolag Stockholm / Sweden

"Heating s or heat" treatment plant "

The invention relates to a system for heating or heat treatment a bed of material carried by the top of an endless, perforated, belt-like conveyor, the upper part of the conveyor passing through at least one

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Warming or heat treatment, in which the warming or heat treatment gas through the top of the j

Conveyor and by the bed conveyed on this as well as by j

ί an optional further layer made of gas-permeable material to j

which is located between the upper part of the conveyor and the j bed.

In systems of the type mentioned, if heavy beds are made of lumpy! Material to be heated to high temperatures, for example-l When sintering pellets from ore concentrate, heavy and complicated conveyor constructions are used with im ι essential self-supporting units, such as grate;

carriage and the like, wherein, in practice, the weight of the movable conveyor part is at least of the same order of magnitude lies like the .. material promoted on this one, and the cost of the plant per amount of material, per unit of time can be heated or heat-treated, are very high. He-

j heating or heat treatment plants with conveyors in the form

ι of endless, perforated belts with relatively little ge ^; important are already known. Previously known funding

However, tape constructions can only be used if the heating should take place at very modest temperatures, for example temperatures up to 300 C, such as in drying plants and the like, with material which

j Dust with abrasive properties is generated, not treated can, if known perforated belt constructions with additional

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orderly support facilities are used.

The aim of the invention is to create a new and advantageous one Device in which the above-mentioned disadvantages are completely or at least largely avoided.

This aim will be achieved with a plant of the above type \ mentioned, wherein the conveyor comprises a plurality of ^counter;

I ■ -.

continuous, non-perforated belt parts adjacent to the i

j, which are separated by perforated areas, the

\ upper conveyor part over at least its entire material

j load-bearing length in the area of the non-perforated belt parts

■ is slidably supported by bearings on the underside! : corresponding non-perforated tape parts act and from

i these parts of the tape are completely covered. In this way,

■ the advantage achieved that a large load-bearing storage area for;

■ the upper part of the conveyor is reached while on very one;

ι ι

; is avoided in a multiple way that abrasive dust between the i belt parts and the bearing elements resting against these belt parts : directions penetrates.

j It is advisable to use the ones to support the non-perforated belt

- parts serving bearings designed as pressure 3? fluid bearings, before-; preferably as a gas cushion bearing, whereby it is possible to! fluid medium to give a flow pattern to the abrasive

¹ Flush dust away from support areas. ^:

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The perforations seen in the conveyor are slits! formed, which preferably extend transversely to the conveying direction, whereby differences in the longitudinal extent of the perforated Areas and the non-perforated belt sections in the longitudinal direction of the conveyor by spontaneous changes in width of the slots can be compensated so that bulges or other deformations of the non-perforated Belt parts are at least largely avoided, while an expansion of the upper conveyor part in his The transverse direction is possible so that the tape is in its perforated areas between the supported non-perforated Areas can sag by a certain amount.

In a particularly simple and therefore preferred embodiment

ί embodiment of the invention, the conveyor has a single J

i endless metal belt, which in the areas between the non-perforated belt parts with heights of successive arranged slots which extend in the transverse direction of the conveyor, the slots are arranged in adjacent rows relative to each other such that the areas between the slots in a row opposite to the slots of the adjacent rows of slots are arranged opposite, and wherein the length of the Slots in each row and the mutual spacing of the slots in that row as well as the distance between the Slots in adjacent rows are designed so that the

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slotted areas of the belt in the longitudinal direction of the conveyor are resilient to different lengths of the with to compensate for the slit areas and the perforated supported belt parts.

According to another advantageous embodiment of the invention these band parts have a plurality of separate endless bands which are arranged laterally next to one another, wherein these bands have brackets arranged along the length of the bands for a plurality of rails which extend transversely to the longitudinal direction of the bands, with the perforations through the space between adjacent ones Rails are formed. This arrangement facilitates the manufacture of the conveyor and enables easy replacement of worn conveyor parts. With this construction can the thermal expansion of the conveyor in its transverse direction can be easily compensated for by arranging the rails in this way be that they are displaceable relative to the brackets in the transverse direction of the conveyor, each of the belts in lateral direction is guided individually.

If the heating or heat treatment system has a plurality of heating or heat treatment zones that extend over are distributed over the length of the system, the direction of flow of the heating or heat treatment gas and / or the flow rate this gas differs in the individual zones

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is, as is normally the case in belt sintering systems, the upper part of the conveyor is loaded with different weights. When gas cushion bearings are used, the correct carrying capacity for the conveyor part may in the various zones can be easily obtained by, not perforated for supporting the • band portions that gas cushion bearing with individually adjustable gas cushion pressures, said Gaspolster- Bearings are arranged separately from one another in the edge region between these zones.

; A number of exemplary embodiments of the invention ! will now be described below with reference to the drawing.

! Fig. 1 shows a schematic representation of a belt sintering plant with an arrangement according to the invention.

Fig. 2 shows on an enlarged scale a sectional view of the

Plant along the line II-II from FIG. 1.

Fig. 3 is a cross-sectional view of an upper part of a j
the box girder with which the upper part of the conveyor is

; cushion is supported.

FIG. 4 shows a plan view of part of the conveyor belt which is used in the system according to FIGS. 1 to 3.

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Fig. 5 is a partial cross-sectional view of another ribbon-like Conveyor that can be used in connection with the arrangement according to the invention.

FIG. 6 shows a plan view of part of the conveyor according to FIG. 5.

FIG. 7 is a cross-sectional view of a portion of the conveyor taken along line VII-VII in FIG. 6.

The pellet sintering system shown in Fig. 1 and 2 is provided with a movable grate 10, which is opposite to the surrounding Atmosphere is shielded and formed by the upper horizontal part of an endless, gas-permeable belt 11, which is guided around driving rollers 12. The entrance part of the grate 12 is a hearth layer 13 made of hot, resistant pellets from a bunker 14 and an upper layer 15 of agglomerated Material in the form of moist, pelletized green pellets or fed to raw pellets, which are burned or sintered in the plant, the raw pellets with the aid of a conveyor 16 can be transported to the grate 12. The grate is transported the bed formed from the two layers of pellets by pre-drying and final drying zones 17, 18, preheating and Final heating zones 19, 20 and pre-cooling and final cooling zones 21, 22. The raw ones Pellets are pre-dried in the pre-drying zone 17 and the pellet bed is cooled in the cooling zone 21 with the aid of a gas, that goes up through the grate 10 and the pellet bed,

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while the bed is in the preheating and final heating zones 19, 20 for burning the dried pellets with the help of a gas. or final heating, which flows from top to bottom through the pellet bed and the grate. Also in the final cooling zone 22 a gas is used that flows through the grate from top to bottom

\ and the pellet bed flows. The final cooling gas consists of cold air which is guided through a line 23 into a pressure chamber 24 which is arranged above the grate 10 near its outlet end. To the side of the grate or below the grate, opposite the pressure chamber 24, a collecting chamber 25 is arranged for receiving the air that is used in the final cooling stage. The warmed up, but essentially relative

\ clean air from the final cooling zone is via a line 26 I.

ί and a fan 27 discharged. ;

: The pre-cooling gas, for example essentially cold air, j ^! is a line 27 and a fan 29 of a pressure. chamber 30 supplied, which is arranged below the grate 10; The gas from this chamber passes upwards through the grate and the bed into a collecting chamber 31. The greater part of the air, which has been used for pre-cooling purposes, flows from the collecting chamber through a main line 32 and branch lines 33 to 35 to the final drying zone 1.8 and to the preheating and final heating zones 19 »20, where they are used as drying

air and used as secondary combustion air for burner 36 j

which are arranged above the pellet bed and are hot

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Generate combustion gases for the pre-heating and final heating stages. The final drying zone 18 and the pre-heating and final heating zones 19 »20 are above the grate from each other and against the pre-drying and cooling zones 18, 21 separated by means of depending walls. Below the grate 10 is a Suction channel 37 arranged in which the gases from the zones 18, and 20 are collected after passing through the grate and bed. The suction chamber 37 is via a line 38

; connected to the suction side of a fan that collects the Gas to a not shown in the drawing

! Gas cleaning system promotes. Excess gas from chamber 3I is withdrawn via a line 40.

The pre-drying of the pellets is achieved with atmospheric air, which is conveyed via a line 41 and a fan 42 into a pressure chamber 43 which is below the grate 10 are arranged. The air flows from the chamber 43 through the grate 10, this air cooling the grate and then through the hot stove material is heated. The heated air then flows further up through the bed, with the moist Layer 15 pellets are predried. The pre-drying air is collected in a suction chamber 44, and is made of this conveyed via a line 45, for example, to a chimney. Alternatively, at least part of the final cooling air can be used for predrying purposes be used.

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At the end of the departure of the Rostee. _10:: is _£: a- Tr ^ ^ RQI iiirioh.turig 46 is arranged. In the Darges in the _Zeiotoiing: t] ellten Außiührungsbeispiel, this lorrneiner the cutting edge, which extends transversely to the Roat unjl _in;> e ^ ug: _on: CDI: e surface of the grate is arranged so that .They · v & as _; Bjett in a location 47 that only. sintered Pelleta h & us. the; jE ^^^ tschiaht, 1.5, and a ply 48 separates the iis _; essential ^ primal material from which

^; Hearth layer 13 contains. The layers 47 and 48 are each led to a not .dangestell "bgn Eörd§r§ ^ _; in the drawing,

^; with which you can still go to a pellet storage place

\ are warm, back to bunker 14, feansgortiert ^ to use as a stove! Layer material used. To

As in detail from Pig. 2 to 4 heryorgelgt, ^ wegist. The conveyor 11 is a relatively thin enjdloises ;: tape aui _{: f} · welciies. can be made of steel. Ba ^ -Band 11, has a plurality of mutually "adjacent endless, unperforated belt parts 49, 50 which are arranged ttber: AJb & i ^ tÄ ^^^^ ungeai ^ _, 52 and are perforated; eggless§; iEiegion © n or Areas 53 separated from each other, are * _; the support devices are fitted with gas cushions ^ bearings l ».; ^ CKBin- _i .Y-oai- _; ^ sf ^ e ^ sluggish ^ cn ... Ye, rsehen on ^^ their top OutletQ ^ niptg © α, _Λ 54- for air or other

Have gas. Every Eastemträger; JjI ^ Qder 52 is ,, f ^ tl.ong its I.

Length with the help of the east support 51 or 52 supporting beam55 (Pig. 1) divided to a plurality of | Gas cushion bearings in the longitudinal direction of the grate 12 one behind the other | to be arranged differently, with groups of mutually adjacent

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ORIGINAL INSPECTED

Gas cushion bearings are provided with devices for the individual generation of the gas cushion pressure. In the illustrated embodiment, the box girders 51 »52 in each group of gas cushion bearings are fed via separate gas supply lines 56, 57, wherein, as in I ¹ Ig. 2, valve devices are provided with which the gas cushion pressure can be adjusted for each group of gas cushion bearings.

; . As can be seen also from Figure 2, the non-perforated band portion 49, which is arranged next to the grating 10, a loading 'siderably greater width than the remaining not orier- perf: th band part 50. The hinge parts 49 are in laterally projecting 'the housing structures along the sides of the sintering plant' arranged. A bead 59 extending in the longitudinal direction of the belt is arranged along each side of the belt 11, which is formed by a glued-on profile made of elastomeric material, which forms a holding element for the stove layer 13 and can be cooled in a controllable manner, as indicated by line 60 and valve 61 in FIG. On top of the top wall 62 of the housing structure, a longitudinal partition 63 extends down to the top surface of the range of the oven and pressurized gas can be passed through a conduit 64 and valve 65 into the area 66 of the housing structure which is outside the wall 63 lies.

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The upper part of the box girder 52 is shown in detail in FIG. As can be seen, the box girder is by his upper side provided with a channel 67 or a plurality of recesses arranged one after the other, into which at least one gas line 54 opens. This upper side can advantageously be made of a material with good sliding properties be coated, for example, as indicated at 68

; suggests using a heat-resistant plastic with a low Coefficient of friction.

Fig. 4 shows a pattern of perforations which is advantageous; can be used when the conveyor belt 11 is in the form of a simple endless, »tape made of, for example, steel.

In this case, the perforations are made up of rows of

■ slots 69, 70 together, extending in the transverse direction of the belt . 11 extend, wherein the slots 70 in a row the loading

! extend between the successive slots 69 of adjacent ones Overlap rows. Furthermore, the lengths of the slots j 69 or 70 in each row and the spacing between the slots! and the distance between the slots 69, 70 of adjacent j

• Rows are formed so that the slotted area 53;

■. '■ i: is slightly resilient in the longitudinal direction of the belt 11, namely;

such that different lengths of the tape

■ 11 in the area 53 and the flanking bleaches 50 none Produce bulging or deformation of the band region 50,

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ORIGINAL INSPECTED

but instead cause only minor changes in the width of the slots 69, 70.

Figures 5 "to 7 illustrate an advantageous alternative Embodiment of the conveyor 11, "in which the non-perforated Belt parts 49, 50 are formed from mutually adjacent endless, individual belts made of, for example, steel. The belts 49, 50 are provided on their underside with pairs of longitudinally extending guide strips 71, which are made of elastic material and are arranged so that they are on a corresponding side of an associated Box girder (51, 52 in Fig. 2) lie. The bands 49, 50 are provided with holders 72 in the manner shown in FIG. 7, which are connected to the belt surface via intermediate elements 73 made of an elastic, heat-resistant material are. For example, the bands 49, 50, as shown in phantom in FIG. 7, carry screw bolts 74 which .Attached by spot welding and on which the elements 73 and holder 72 are placed and then secured with a nut 75.

The holders 72 are each provided with a head 76, under which grooves are arranged which extend transversely to the belt 59 or 50 and receive longitudinally displaceable, inwardly directed flanges 77 of profile rails 78 which, seen in cross section, are essentially semicircular Upper

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have area. The rails 78 are spaced from one another in such a way that they have openings 79 in the areas between the belts 49, 50 for the passage of heating or heat treatment gas through the upper part of the conveyor 11 '. set free.

i The invention is used in connection with a sintering plant

I because it is particularly important in this connection.

! termed gate parts with it. However, the invention is not

! to this use and not to the one in the drawing

\ illustrated embodiment, but can be used in

; Modified within the scope of the claims.

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Claims (8)

Aug. 29, 1980 Dipl.-Ing. Dipl.-Ing. H.-]. Lippert Patentanwälte Frankenforster Straße 137 Bergisch G! Adbadh3 luossavaara-Kiirunavaara Aktiebolag Stockholm / Sweden Claims 1. Arrangement in a system for heating or heat treatment a bed of material carried by an upper part of an endless conveyor in the form of a perforated belt is, the upper part by at least one heating or Heat treatment zone extends in which heating or heat treatment gas passes through the upper part and the bed conveyed on this, as well as by an optional another layer of gas-permeable material is passed between the upper part of the conveyor and the bed is arranged thereby characterized in that the conveyor (11) a plurality of mutually adjacent endless, non-perforated belt parts (49, 50), which through perforated Areas (53) are separated from one another, the upper conveyor part (10) along at least substantially its entire material-bearing length in the area of the non-perforated belt parts (49, 50) by bearings (51, 52, 56, 57, 58), which correspond to the underside of 1300U / 1064 the, non-perforated tape parts and completely from! these band parts (49, 50) ″ are covered, sliding away is based. : 2. Arrangement according to claim 1, characterized in that the bearings are designed as fluid pressure bearings; are formed. | 3. Arrangement according to claim 2, characterized! ι ι draws that the fluid pressure bearing as a gas cushion-j ; Bearings are formed. ; ! I. ι ί j ■ i 4. Arrangement according to one of claims 1 to 3, characterized! i ι · characterized in that the perforations as j Slots (69, 70, 79) are formed, which are essentially j ί borrowed extend transversely to the conveyor (11). j j 5. Arrangement according to claim 4, characterized in that the conveyor (11) is a single,
having endless metal belt, which in the area (53) between the non-perforated Bandtdlen (49, 50) with rows
is provided by successively arranged slots (69, 70) extending transversely of the conveyor, wherein
the slots (69, 70) are arranged in adjacent rows relative to one another so that the areas between the 1300U / 106A Slots (70) are arranged in one row opposite slots (69) in adjacent rows of slots, and wherein the Length of the slots (69, 70) in each row and the mutual spacing between the slots in that row as well as the distance between the seat strands in adjacent ones Rows are chosen so that the slotted areas of the belt in the longitudinal direction of the conveyor to compensate for different Longitudinal expansions of the areas (53) perforated with the slots and the non-perforated supported Band areas (49, 50) are designed to be resilient. 6. Arrangement according to one of claims 1 to 4, characterized characterized in that the belt regions (49, ■ 50) have a plurality of separate endless belts, which are arranged side by side, that the bands are provided with holders (72), which along the Length of the straps are attached to the support of a plurality of rails (70) which extend transversely to the longitudinal direction of the belts extend, and that the perforations are formed by the distances between adjacent rails (73) are. 7. Arrangement according to claim 6, characterized in that the rails (78) relative to the Holders (72) in the transverse direction to the conveyor (11) 1300U / 1064 are slidable, each of the ligaments in a lateral direction is performed individually. 8. Arrangement according to one of claims 3 to 7, wherein the Heating or heat treatment plant has a plurality of heating or heat treatment zones which run along the length of the plant are arranged, and in which the flow direction of the heating or heat treatment gas and / or the flow rate of the gas in corresponding zones is different, so that a corresponding Difference in pressure of the gas cushion bearing is required characterized in that each . of the imperforate tape parts (49, 50) are supported by a plurality of gas pad bearings (51, 52, 56, 57, 53) which are separated from one another in the edge region between the zones (17 to 22). 130014/1064